Let me make an observation about the term "soft determinism." Although I do not completely oppose its use, it does seem to be loaded language, and allows its adherents to appear better than they really should.
Now, "soft" determinism is used in contrast with "hard" determinism. Using these terms, the popular Reformed/Calvinistic position, which is compatibilism, would be called "soft" determinism, whereas my position would be called "hard" determinism.
The former is "softer" in quality and/or in quantity regarding the level and/or amount of control (determinism) that God exercises over his creation, whereas "hard" determinism is absolute, affirming that God exercises complete (in level or quality) and comprehensive (in amount or quantity) control over everything.
But this means that "soft" determinism is really partial determinism – that is, partial (not full) either in quality or in quantity, or both. And if what God does not absolutely determine can still actually happen, then this means that there is another (one or more) determining power in the universe. When we are speaking of God's relation to man, attributing only partial determinism to God necessarily implies attributing partial determinism to man also. So this becomes a version of dualism.
In other words, one who believes that God absolutely determines everything is a full determinist, since he believes that God fully determines everything, in terms of both quality and quantity, and in terms of both the level (extent) and the amount of control exercised. To believe anything less than this is not full; therefore, it is partial.
Also, since "soft" determinism really means partial determinism, this also necessarily means that it is partial indeterminism (that is, partial non-determinism). Granted, since Calvinists usually (claim to) affirm greater determining power to God than man, this indeterminism is a very "soft" indeterminism, but it is still partial indeterminism.
It becomes just a matter of emphasis as to which term one wishes to use. So the term "soft" determinism is at least a little misleading, making its adherents look better than they really should. To some, it has the effect of sounding "softer," kinder, and less extreme. But if we don't let the language deceive us, we see that it is really partial determinism, weak determinism, incomplete determinism, or "soft" indeterminism. And, at least by implication, dualism.
On the other hand, since we who affirm "hard" determinism in fact affirm just "determinism," there is no need to qualify it if not for a contrast or a challenge from a partial version. I do not need to constantly say that I am a full human unless I am in a discussion involving partial humans – I am just human. And in the context of a contrast, what we affirm is really full determinism, not "hard." Also, when we flip it around, we can confidently say that we affirm non-indeterminism (zero indeterminism) when it comes to the level and amount of control that God exercises over his creation.
Of course, the above does not directly argue about the merits of the two views, but it is an observation about the loaded language often used.